Comparative investigation on dry sliding wear behaviour of L-PBF printed tool steel for stamping dies

Additive manufacturing through Laser Powder Bed Fusion (L-PBF) offers significant advantages for tooling applications. However, its implementation in high-load tribological conditions is limited by process-induced defects. In this study, the dry sliding wear behaviour of L-PBF fabricated maraging steel was scientifically investigated under high-load conditions (150 N), demonstrating industrial stamping operations and compared with conventionally manufactured AISI D2 tool steel. Both materials were heat-treated to attain a comparable hardness of 9.74 ± 0.43 GPa (~ 58–60 HRC) to enable a reasonable performance evaluation. The results reveal that the L-PBF maraging steel shows a significantly higher specific wear rate (on order of 10 − 6 mm 3 /Nm) and a comparatively higher and less stable coefficient of friction than AISI D2 steel. Comprehensive FESEM analysis of worn surfaces shows that defects such as microporosity, lack of fusion, and microcracks act as stress concentrators and enable abrasive particle entrapment, leading to severe three-body abrasive wear. Nanoindentation results further confirm defect-induced deformation behaviour through distinct pop-in events, establishing a direct correlation between microstructural heterogeneity and tribological degradation. Similar to conventional low-load studies, the present high-load study highlights the critical role of defect-driven mechanisms in governing wear performance. The findings reveal that attaining high hardness alone is insufficient for ensuring wear resistance in L-PBF tool steels and highlight the necessity of defect control for reliable application in stamping die conditions.